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The minimum number of Cs that can be associated with one A is 1. I know this because the existence of the C to A relationship is mandatory. The maximum number of Cs that can be associated with one A is unlimited (or many). I know this because the cardinality of the C to A relationship is 1-M. | Entity-Relationship Exercise Exercise ER-1 Exercise ER-2 Exercise ER-3 Exercise ER-4 Exercise ER-5 Exercise ER-6 Exercise ER-7 The minimum number of Cs that can be associated with one A is 1. I know this because the existence of the C to A relationship is mandatory. The maximum number of Cs that can be associated with one A is unlimited (or many). I know this because the cardinality of the C to A relationship is 1-M. Exercise ER-8 Diagrams 1, 2, 3, and 4 are consistent with the facts. Diagram 2 is consistent because, although Jennifer leads more than one project, the diagram is ambiguous as regards to cardinality — it merely points out that the existence is optional. Diagram 4 is also consistent with the facts because of its ambiguity regarding existence, this time in both directions. 1 2 3 4 1 2 3 4 Exercise ER-9 1 2 3 4 1 2 3 | Entity-Relationship Exercise Exercise ER-1 Exercise ER-2 Exercise ER-3 Exercise ER-4 Exercise ER-5 Exercise ER-6 Exercise ER-7 The minimum number of Cs that can be associated with one A is 1. I know this because the existence of the C to A relationship is mandatory. The maximum number of Cs that can be associated with one A is unlimited (or many). I know this because the cardinality of the C to A relationship is 1-M. Exercise ER-8 Diagrams 1, 2, 3, and 4 are consistent with the facts. Diagram 2 is consistent because, although Jennifer leads more than one project, the diagram is ambiguous as regards to cardinality — it merely points out that the existence is optional. Diagram 4 is also consistent with the facts because of its ambiguity regarding existence, this time in both directions. 1 2 3 4 1 2 3 4 Exercise ER-9 1 2 3 4 1 2 3 | Entity-Relationship Exercise Exercise ER-1 Exercise ER-2 Exercise ER-3 Exercise ER-4 Exercise ER-5 Exercise ER-6 Exercise ER-7 The minimum number of Cs that can be associated with one A is 1. I know this because the existence of the C to A relationship is mandatory. The maximum number of Cs that can be associated with one A is unlimited (or many). I know this because the cardinality of the C to A relationship is 1-M. Exercise ER-8 Diagrams 1, 2, 3, and 4 are consistent with the facts. Diagram 2 is consistent because, although Jennifer leads more than one project, the diagram is ambiguous as regards to cardinality — it merely points out that the existence is optional. Diagram 4 is also consistent with the facts because of its ambiguity regarding existence, this time in both directions. 1 2 3 4 1 2 3 4 Exercise ER-9 1 2 3 4 1 2 3 4 | Entity-Relationship Exercise Exercise ER-1 Exercise ER-2 Exercise ER-3 Exercise ER-4 Exercise ER-5 Exercise ER-6 Exercise ER-7 The minimum number of Cs that can be associated with one A is 1. I know this because the existence of the C to A relationship is mandatory. The maximum number of Cs that can be associated with one A is unlimited (or many). I know this because the cardinality of the C to A relationship is 1-M. Exercise ER-8 Diagrams 1, 2, 3, and 4 are consistent with the facts. Diagram 2 is consistent because, although Jennifer leads more than one project, the diagram is ambiguous as regards to cardinality — it merely points out that the existence is optional. Diagram 4 is also consistent with the facts because of its ambiguity regarding existence, this time in both directions. 1 2 3 4 1 2 3 4 Exercise ER-9 1 2 3 4 1 2 3 4
